I am wanting to power multiple sensors (around 10) MPU6050 each at the end of cables that are approximately 1.5m in length. The issue I am having is that each MPU6050 requires 3.3v and the arduino Due I am using outputs either 3.3v or 5v however I believe the Due doesnt handle receiving 5v as input so I am a bit unsure if I can just boost the power to 5v without needing to reduce the power again before I read the sensor values.
At the moment I have 4/5 sensors running without any issues but they are plugged directly into the breadboard. My problem occurs when I add a length of cable between the breadboard and my sensor, the sensor appears to be getting power but after a short duration I stop receiving values from the MPU6050 sensor. This is leading me to believe the issue is now probably power related as swapping the cable with another cable yields the same results.
I am a programmer by profession so the coding part was relatively easy but when it comes to the amount of power required to run something I am struggling to find the information.
The questions I am asking are;
Is there a way to calculate how much power needs to be supplied based on the number of sensors and the length of cables used?
What is the best way to supply enough power to multiple sensors? Without damaging the Due/sensors
I'd try putting a cap (highest value ceramic I had) next to the MPU board between power and ground for starters, to rule out power problems
You know you have sufficient supply power, so the only way it could be a power issue is if the voltage droops briefly when it tries to draw current due to the inductance of the cable. That sensor doesn't use much power, so it's unlikely that the resistance of the cable is the problem.
It could also be noise on the signal lines, though - How long are the cables, anyway? I2C isn't really meant for long distance data transmission - you shouldn't go beyond a like a couple of meters of wire on one I2C bus under normal conditions.
I will get hold of a capacitor and see if that helps, would you recommend a cap for each sensor or just one where the power comes into the breadboard? Any rough ideas on size of cap? (sub 100 or over 100nf)
The cables I am using are short, only 1.5 - 2 metres for each sensor from the breadboard (Which is under the limit you mentioned) but noise could be an issue as they are basically old telephone cables ive re-purposed while I see if the idea works so I have no idea the quality of the cables. I have tried 2 cables and both cause the system to give values for a short time (Varies from few seconds to couple of minutes) then stops responding.
if the cap doesnt help the issue is there a way to reduce noise on the cable? Would something like a ferrite bead do the trick?